... ,such as 1022,1018,1010,1008,1015...Medium carbon steel are 35k,45#,10B21,1035,CH38F,1039 ... ,anodized ,Parkerising,and Environmental Plated is used in our products,Hexavalent chromium are accord with ROHS ... 100 equipment to produce fastener.Perfect quality 1.In Carbon Steel,The material are always use C1022 ,The ... 0.18%-0.23% ,is higher than other Carbon Steel .2.Fasteners' Head is much thicker than ...